Improvement in insteuments poe dbawing ellipses



A. WARR.

INSTRUMENT FOR DRAWING ELLIPSES.

No. 63,123. Patented Mar. 19, 1867.

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AARON WARE, OF L OCKPORT, NEW YORK.

Letters Patent N ;.63,12'3, 'clated M'arcli 19, 1867.

IMPROVEMENT'IN INSTRUMENTS FOR DRAWING ELLIPSES.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, AARON WARR, of Loclrport, in the county of Niagara, and State of New York, have invented a certain new and improved Instrument for Drawing Ellipses; and I do hereby declare that the following is a full and excel; description thereof, reference being bad to the accompanying drawing, which is a. perspective view of my instrument in the position for drawing an ellipse.

The object of my improvemeutis the construction of aninstruinent for the use of draughtsmen and others, by which ellipses of different sizes and of varying eccentricity can be readily-described; and the invention consists of a pair of' dividers, one leg of which is provided with a device for keeping the instrument, while it is I being operated, in an upright position, while the other leg is provided with a. sliding sleeve or collar, to which isjointed a. suitable arm for holdingthc pen or pencil.

In the drawing, AB represent the two legs of an ordinary pair of compasses or dividers; C the doublebracing device attached to the former; and D the marking and operating device, consisting ofv the slidingsle'evc e, and the pen and pencil-holder f, which is jointed to the sleeve 0, or to a 'short arm, g, extending from the same, as represented. If required,'this joint may be provided with any suitable attachment or set-screw for rendering it rigid, so as to prevent the possibility of any movement of the some as the ellipse is being drawn. The device-C consists of two diverging legs h h, preferably attached to a collar, 1', provided with a set-screw,- n, for securing the same in place. These logs should be so adjusted that their feet will be in a line at right angles with theline a: :c, which connects the points of the legs A B of the dividers. If preferred, these braces may be rigidly attached, by welding or otherwise, to the leg A, in the position above described.

My improved instrument is operated as follows: From the centre a, of the ellipse to be described, a line, a: z, is, first drawn in the direction of the major or conjugate axis. The point n, of the pen or pencil, is next adjusted at a distance from the foot of B equal to half the minor or transverse axis of the ellipse. The foot of the leg D is then placed at the'centre, o, and the foot ofleg A adjusted along the line ."0 :c, at such a distance from the point 0 aswill incline the leg- B till the point of the pencil, when brought in contact with the paper in the line a: x, will be at one of the extremities of the major axis, as shown. The foot of A being fixedin this position, the braces It h prevent the top of the instrument from inclining to eitherside from a. perpendicular. By turning the device I) about its inclined axis B, the pen or pencil being kept in contact with. the paper, will describe the required ellipse, thesleevc c sliding freely up and down its axis, as required, and represented in red lines. I I

From the above it will bc readily perceived that an ellipse oi any size that the dimensions of the instrument will allow (which may be of different sizes) may be readily drawn, and of an eccentricity that may be varied by inclining theleg B (as before described) more or less from a perpendicular, the ellipse approximating to a circle as the'legB becomes less inclined, as shown by the ellipse in red lines. The leg B and arm f, if desired, may either or both be provided with another joint similar in construction and use to that in common circular pens. The sleeve e should be of sufficient length to hold the pencil steadily, and should be loose enough upon the axis B to allow it to easily slide up and down the same. 7

The advantages of myimpro'vcment' are obvious to those accustomed to drawing ellipses, the amount of time, labor, and vexation that is saved thereby,.rendering the invention one of great importance. The instrument is also simplc'of construction. Besides, it is of such a nature as adapts it to drawing ellipses of much smaller size than the instruments now in use, and the ease with'which the eccentricity can be varied is an advantage which has not, that I am aware of, beenuttained by any other instrument.

What I claim as my invention, and desire to secure by Letters Patent, is I The combination, with a. pair of dividers, of the penand pencil-carrier f, jointed to a sleeve 2, or equivalent, which enables the device to slide up and down and turn upon the inclined bar or leg B of the dividers, arranged and operating substantially as set forth.

I also claim, in combination therewith, n, substantially as and for the purpose specified. 1

'gned my name in the presence of two subscribing witnesses.

In witness whereof I have hereunto s1 AARON WARE.

the double brace 0, consisting of the legs It It, collar 1', and set-screw Witnesses WILLIAM M onss. SAML'. Mouse. 

